JP6555891B2 - Mobile communication terminal and control method of mobile communication terminal - Google Patents

Description

  The present invention relates to a portable communication terminal having a sleep function for putting a CPU in a dormant state and a method for controlling the portable communication terminal.

  2. Description of the Related Art PHS (Personal Handy-phone System) terminals, mobile phones, smartphones, and the like are widely used as mobile communication terminals that perform telephone calls and data communication by performing wireless communication with a base station of a mobile communication network. When a problem occurs that affects the communication quality (hereinafter referred to as an event) during communication with the base station, the mobile communication terminal maintains the communication quality by performing event response processing to resolve this event. ing. For this reason, conventional mobile communication terminals always monitor the occurrence of events during communication.

  As shown in FIG. 6, a conventional mobile communication terminal 20 which is a PHS terminal, for example, includes an antenna 21 and a radio frequency (RF) unit 22 that transmit and receive a frame in which audio data and the like are modulated with a base station, A baseband unit 23 that processes a band signal and a CPU (Central Processing Unit) 24 that controls each unit are provided.

  The CPU 24 constantly monitors the occurrence of an event during communication, and executes an event response process when the event occurs. For example, the CPU 24 evaluates the communication quality based on the received signal strength (RSSI: Received Signal Strength Indicator) transmitted from the AD measurement circuit 231 of the baseband unit 23, and the communication quality is deteriorated. First, it is determined that an event has occurred, and event response processing such as interference avoidance processing is executed. Further, when the occurrence of a CRC (Cyclic Redundancy check) error is notified from the channel codec 232 of the baseband unit 23, the CPU 24 is based on a frame error rate (FER) that is a communication error occurrence rate. When the communication quality is evaluated and the communication quality is deteriorated, it is determined that an event has occurred, and interference avoidance processing is performed. Further, when an interrupt signal is transmitted from the interrupt generation circuit 233 of the baseband unit 23 every time a frame is received, the CPU 24 confirms a control message that is instruction information transmitted along with the frame. The occurrence of an event based on a control message is monitored.

  By the way, since there are many opportunities for portable communication terminals to be taken outside and used, it is desired to extend the driving time by batteries. Although not related to a mobile communication terminal, for example, in a sensor network that collects information by connecting a plurality of wireless sensors to a network, the CPU of the wireless sensor is set to a sleep mode in a sleep state, and the sensor network management device In some cases, when a wake-up signal is received by a wireless sensor, the CPU is returned from the sleep mode to the normal mode (see, for example, Patent Document 1). According to the invention described in Patent Document 1, since the CPU with high power consumption is set in the sleep mode, the power consumption of the wireless sensor is reduced and the driving time by the battery becomes long.

JP 2010-109959 A

  If the CPU of the portable communication terminal is put into a hibernation state using the technology disclosed in Patent Document 1, the power consumption of the mobile communication terminal is reduced, and the driving time by the battery becomes longer. However, since the conventional mobile communication terminal 20 constantly monitors the occurrence of an event by the CPU 24 during a call, the CPU 24 cannot be put into a sleep state.

  An object of the present invention is to provide a mobile communication terminal that puts a CPU in a dormant state while constantly monitoring the occurrence of an event due to communication with a base station, and a method for controlling the mobile communication terminal.

In order to solve the above-mentioned problems, the invention of claim 1 includes communication means for communicating with a base station, a normal mode for processing an event generated by communication with the base station, and a sleep mode in a dormant state. An event monitoring unit that monitors the occurrence of the event, outputs an interrupt signal to the CPU when the event occurs, and switches the CPU from the sleep mode to the normal mode. The event monitoring means is transmitted from the base station, which determines whether or not the event has occurred based on the communication quality with the base station, and requires event handling processing by the CPU. An instruction determination unit that determines whether or not the event has occurred based on a control message that is instruction information, and the communication quality determination unit includes: The average RSSI obtained by averaging the RSSI of the signal received from the ground station is compared with a preset average RSSI threshold, and it is determined that the event has occurred when the average RSSI is lower than the average RSSI threshold. An RSSI determination unit, an averaged FER obtained by averaging FERs based on communication errors generated in communication with the base station, and a preset average FER threshold value are compared, and the averaged FER is greater than the average FER threshold value. A FER determination unit that determines that the event has occurred when the event is high.

The invention according to claim 2 is characterized in that the event monitoring means is constituted by an FPGA .

According to a third aspect of the present invention, there is provided a communication means for communicating with a base station, a CPU including a normal mode for processing an event generated by communication with the base station, and a sleep mode for entering a sleep state; Event monitoring means for monitoring occurrence, outputting an interrupt signal to the CPU when the event occurs, and switching the CPU from the sleep mode to the normal mode, the event monitoring means, Based on the communication quality with the base station, a communication quality determination unit that determines whether or not the event has occurred, and a control message that is transmitted from the base station and requires instruction handling processing by the CPU An instruction determination unit that determines whether or not the event has occurred based on the signal received from the base station. An RSSI determination unit that compares an average RSSI obtained by averaging RSSI and a preset average RSSI threshold, and determines that the event has occurred when the average RSSI is lower than the average RSSI threshold; An averaged FER obtained by averaging FERs based on communication errors that occur in communication with a station is compared with a preset average FER threshold value, and the event occurs when the averaged FER is higher than the average FER threshold value. An event monitoring step for monitoring whether or not an event that requires processing by the CPU has occurred during communication with the base station, When the event occurs, an interrupt signal is output to the CPU, and the CPU processes the event from a sleep mode that is in a sleep state. Comprising a mode switching step of switching to the normal mode, and characterized in that.

According to the first and third aspects of the present invention, since the event monitoring means monitors events that occur during communication with the base station, the CPU can be switched to the sleep mode. Therefore, while the CPU is set in the sleep mode, the power consumption of the mobile communication terminal is reduced, so that the battery maintenance time (usable time) becomes longer.
In addition, since events that occur due to different causes such as communication quality with the base station and instructions from the base station are monitored, the CPU is switched from the sleep mode to the normal mode at an appropriate timing.
Furthermore, since the occurrence of an event due to communication quality is monitored based on different indexes such as RSSI and FER, the CPU is switched from the sleep mode to the normal mode at an appropriate timing.
Furthermore, since the CPU is switched to the sleep mode when the control by the CPU during the call operation is unnecessary, the control of the mobile communication terminal is not hindered.

According to the second aspect of the present invention, since the event monitoring means is constituted by the FPGA, the event monitoring operation can be easily changed only by changing the program of the FPGA.

1 is a schematic block diagram showing a mobile communication network according to an embodiment of the present invention. It is a schematic block diagram of a mobile communication terminal according to an embodiment of the present invention. 2 is a flowchart showing an operation in the case of monitoring the occurrence of an event based on RSSI in the mobile communication terminal of FIG. 1. 2 is a flowchart showing an operation when the occurrence of an event is monitored based on FER in the mobile communication terminal of FIG. 1. 2 is a flowchart showing an operation in the case of monitoring the occurrence of an event based on a control message from a base station in the mobile communication terminal of FIG. It is a schematic block diagram of the conventional portable communication terminal.

  The present invention will be described below based on the illustrated embodiments.

  1 and 2 show an embodiment of the present invention, and FIG. 1 is a schematic block diagram showing a mobile communication network 1 according to this embodiment. The mobile communication network 1 includes a plurality of mobile communication terminals 2 and 3, a plurality of base stations 4, 5 and 6, and a public line network 7 to which the plurality of base stations 4, 5 and 6 are connected.

  The mobile communication terminals 2 and 3 are, for example, a PHS terminal, a mobile phone, or a smartphone. The plurality of base stations 4, 5, 6 are provided with predetermined communicable ranges 41, 51, 61 capable of wireless communication with the mobile communication terminals 2, 3, respectively. The communicable ranges 41, 51, 61 of the base stations 4, 5, 6 partially overlap with the communicable ranges of the adjacent base stations. Although only two mobile communication terminals and three base stations are depicted in order to avoid complication of the drawings, the actual mobile communication network 1 is configured by a large number of mobile communication terminals and base stations.

  As shown in FIG. 2, the mobile communication terminal 2 is, for example, a PHS terminal, and mainly includes an antenna 8 and an RF unit 9 that transmit and receive a frame in which audio data and the like are modulated with a base station 4, and a baseband signal. And a baseband unit 10 for processing. In addition, the mobile communication terminal 2 controls the FPGA (event monitoring means) 11 that monitors the occurrence of an event during communication with the base station 4 and each part of the mobile communication terminal 2, and according to the event monitoring result of the FPGA 11. CPU12 which performs an event response process. The CPU 12 can be switched between a normal mode in which various processes such as an event response process are performed and a sleep mode in a hibernation state.

  The antenna 8 is connected to the RF unit 9, and the RF unit 9 is connected to the baseband unit 10. The baseband unit 10 is connected to the CPU 12 via the FPGA 11. The antenna 8, the RF unit 9, and the baseband unit 10 correspond to communication means of the present invention.

  The baseband unit 10 includes a modem 101 that modulates and demodulates a frame, and an AD measurement circuit 102 that A / D converts the RSSI transmitted from the RF unit 9 and transmits the converted AD measurement value to the FPGA 11. The baseband unit 10 also includes a channel codec 103 that performs frame configuration and analysis to detect the occurrence of a CRC error, and an interrupt generation circuit 104 that transmits an interrupt signal to the CPU 12 each time a frame is received from the base station 4. With.

  An FPGA (Field Programmable Gate Array) 11 is an integrated circuit / device equipped with a predetermined program, and includes a communication quality determination unit 111 that determines whether an event has occurred based on the communication quality with the base station 4. Prepare. The FPGA 11 includes an instruction determination unit 112 that determines whether an event has occurred based on a control message that is instruction information transmitted from the base station 4.

  The communication quality determination unit 111 includes an RSSI determination unit 113 that monitors the occurrence of an event based on the AD measurement value transmitted from the AD measurement circuit 102, and the occurrence of an event based on the CRC error notification transmitted from the channel codec 103. FER determination unit 114 for monitoring the above. The RSSI determination unit 113 and the FER determination unit 114 include storage units 113a and 114a in which an average RSSI threshold value and an average FER threshold value used for communication quality evaluation are stored, respectively.

  Next, event monitoring and event response processing based on RSSI will be described with reference to FIG. For example, the CPU 12 shifts from the normal mode to the sleep mode during the call operation. Since the power consumption of the mobile communication terminal 2 is reduced when the CPU 12 is in the dormant state, the driving time of the mobile communication terminal 2 by the battery becomes longer than when the CPU 12 is in the normal mode.

  The AD measurement circuit 102 of the baseband unit 10 acquires RSSI from the RF unit 9 every time the RF unit 9 receives a frame from the base station 4, and performs A / D conversion on the RSSI to calculate an AD measurement value. The AD measurement circuit 102 transmits an AD measurement value to the RSSI determination unit 113 after transmitting a reception timing signal indicating completion of reception to the RSSI determination unit 113 of the FPGA 11.

  The RSSI determination unit 113 performs an averaging process of the AD measurement value in order to remove the influence of noise and sudden fluctuation from the RSSI, and calculates an average RSSI. Next, the RSSI determination unit 113 compares the averaged RSSI with the average RSSI threshold stored in the storage unit 113a, and when the averaged RSSI is lower than the average RSSI threshold, an event of communication quality degradation occurs. It is determined that The processing so far corresponds to the event monitoring step of the present invention. The RSSI determination unit 113 transmits an interrupt signal to the CPU 12 when determining that the communication quality has deteriorated. This process corresponds to the mode switching step of the present invention.

  The CPU 12 shifts from the sleep mode to the normal mode by an interrupt signal, and transmits a status confirmation signal to the FPGA 11 in order to confirm the communication quality evaluation based on the RSSI. In response to the status confirmation signal, the RSSI determination unit 113 notifies the CPU 12 that the averaged RSSI is lower than the average RSSI threshold. The CPU 12 performs interference avoidance processing such as base station switching as event response processing for communication quality degradation.

  Next, with reference to FIG. 4, event monitoring and event response processing based on FER will be described. Similar to event monitoring based on RSSI, the CPU 12 shifts from the normal mode to the sleep mode during the call operation.

  The channel codec 103 of the baseband unit 10 analyzes the frame demodulated by the modem 101 and detects the occurrence of a CRC error in order to confirm whether or not the frame has been correctly received by the RF unit 9. The channel codec 103 transmits a reception timing signal to the FER determination unit 114 of the FPGA 11 after frame analysis. The FER determination unit 114 transmits a status confirmation signal to the FPGA 11 in order to confirm the occurrence of a CRC error. The channel codec 103 notifies the presence / absence of a CRC error in response to the status confirmation signal.

  The FER determination unit 114 calculates the FER based on the notification result from the channel codec 103, performs the FER averaging process to remove the influence of noise and sudden fluctuation, and calculates the average FER. Next, the FER determination unit 114 compares the averaged FER with the average FER threshold value stored in the storage unit 114a. If the averaged FER is higher than the average FER threshold value, an event of communication quality deterioration occurs. It is determined that The FER determination unit 114 transmits an interrupt signal to the CPU 12 when determining that the communication quality has deteriorated.

  The CPU 12 shifts from the sleep mode to the normal mode by the interrupt signal, and transmits a status confirmation signal to the FPGA 11 in order to confirm the communication quality evaluation based on the FER. In response to the status confirmation signal, the FER determination unit 114 notifies the CPU 12 that the averaged FER is higher than the average FER threshold. The CPU 12 performs interference avoidance processing such as base station switching as event response processing for communication quality degradation.

  Next, event monitoring and event response processing based on a control message from the base station 4 will be described with reference to FIG. Similar to event monitoring based on RSSI and FER, the CPU 12 shifts from the normal mode to the sleep mode during the call operation.

  When the channel codec 103 analyzes the frame, the interrupt generation circuit 104 of the baseband unit 10 transmits an interrupt signal to the instruction determination unit 112 of the FPGA 11. When the instruction determination unit 112 receives the interrupt signal, the instruction determination unit 112 transmits a status confirmation signal to the interrupt generation circuit 104 in order to confirm a control message transmitted through an associated control channel (ACCH) of the frame. The interrupt generation circuit 104 transmits a control message to the instruction determination unit 112 in response to the status confirmation signal.

  The instruction determination unit 112 performs no processing when there is no control message, but transmits an interrupt signal to the CPU 12 when receiving a control message that requires event response processing by the CPU 12. Control messages that require event response processing by the CPU 12 include, for example, “RR reception”, “network-side disconnection”, and a high-speed associated control channel (FACCH) transmitted by a low-speed associated control channel (SACCH; Slow Associated Control Channel). There is a “TCH switching instruction” transmitted by Fast Associated Control Channel). “RR (Receive Ready) reception” is a control message for confirming the continuation of the communication state from the base station 4 to the mobile communication terminal 2. “Network side disconnection” is a control message for notifying communication disconnection from the public line network. The “TCH switching instruction” is a control message instructing switching of the base station.

  The CPU 12 shifts from the sleep mode to the normal mode by the interrupt signal, and transmits a status confirmation signal to the FPGA 11 in order to confirm the control message. The interrupt generation circuit 104 transmits a control message to the CPU 12 in response to the status confirmation signal. The CPU 12 executes event response processing according to the control message. For example, for “RR reception”, the CPU 12 executes an RR transmission process for transmitting an RR signal to the base station 4. For “network side disconnection”, the CPU 12 also executes a disconnection process for disconnecting communication from the mobile communication terminal 2 side. Further, in response to the “TCH switching instruction”, the CPU 12 executes a TCH switching process for switching the connection to a base station having a good radio wave condition.

  As described above, according to the mobile communication terminal 2 that implements the present invention, events that occur during communication with the base station 4 are monitored by the FPGA 11, so that the CPU 12 can be switched to the sleep mode. Therefore, while the CPU 12 is set to the sleep mode, the power consumption of the mobile communication terminal 2 is reduced, and the battery maintenance time (usable time) is lengthened.

  Also, since the event that occurs based on the communication quality is monitored by the communication quality determination unit 111 and the event that occurs based on the control message is monitored by the instruction determination unit 112, the communication quality with the base station 4 and the base station 4 Events that occur due to different causes such as instructions are monitored. Therefore, the CPU 12 switches from the sleep mode to the normal mode at an appropriate timing.

  Furthermore, since the occurrence of the event due to the communication quality is monitored by the RSSI determination unit 113 and the FER determination unit 114 based on different indexes of RSSI and FER, the CPU 12 switches from the sleep mode to the normal mode at an appropriate timing.

  In addition, since the CPU 12 enters the sleep mode during a call operation that does not require control by the CPU 12, the control of the mobile communication terminal 2 is not hindered. Furthermore, since the FPGA 11 is used to monitor the occurrence of an event, the event monitoring operation can be easily changed only by changing the program of the FPGA 11.

  Although the embodiment of the present invention has been described above, the specific configuration is not limited to the above embodiment, and even if there is a design change or the like without departing from the gist of the present invention, Included in the invention. For example, in the above embodiment, the occurrence of an event is monitored based on the communication quality with the base station 4 and the control message from the base station 4, but the event is made using only one of them. Occurrence may be monitored. Moreover, although event occurrence based on communication quality is monitored based on RSSI and FER, event occurrence may be monitored using only one of them. Furthermore, the index used for evaluating the communication quality and the type of control message are not limited to the above embodiment, and other events and control messages not explicitly described in the above embodiment are used to monitor event occurrence. May be.

  Furthermore, although the event monitoring means is configured by the FPGA 11, it may be configured by, for example, an ASIC (Application Specific Integrated Circuit) or a CSSP (Customer Standard Standard Products).

2, 3 Mobile communication terminal 4-6 Base station 8 Antenna 9 RF unit 10 Baseband unit 11 FPGA
12 CPU
111 Communication quality determination unit 112 Instruction determination unit 113 RSSI determination unit 114 FER determination unit

Claims (3)

A communication means for communicating with the base station;
A CPU having a normal mode for processing an event generated by communication with the base station, and a sleep mode for entering a sleep state
Event monitoring means for monitoring the occurrence of the event, outputting an interrupt signal to the CPU when the event occurs, and switching the CPU from the sleep mode to the normal mode,
The event monitoring means includes:
A communication quality determination unit that determines whether or not the event has occurred based on communication quality with the base station;
An instruction determination unit that determines whether or not the event has occurred, based on a control message that is transmitted from the base station and is instruction information that requires event response processing by the CPU ;
The communication quality determination unit
The average RSSI obtained by averaging the RSSI of the signal received from the base station is compared with a preset average RSSI threshold, and it is determined that the event has occurred when the average RSSI is lower than the average RSSI threshold. An RSSI determination unit,
An averaged FER obtained by averaging FERs based on communication errors generated in communication with the base station is compared with a preset average FER threshold value, and the event is detected when the averaged FER is higher than the average FER threshold value. A FER determination unit that determines that has occurred,
A mobile communication terminal characterized by the above. The event monitoring means is constituted by an FPGA.
The mobile communication terminal according to claim 1. A communication means for communicating with the base station;
A CPU having a normal mode for processing an event generated by communication with the base station, and a sleep mode for entering a sleep state
Event monitoring means for monitoring the occurrence of the event, outputting an interrupt signal to the CPU when the event occurs, and switching the CPU from the sleep mode to the normal mode,
The event monitoring means includes:
A communication quality determination unit that determines whether or not the event has occurred based on communication quality with the base station;
An instruction determination unit that determines whether or not the event has occurred, based on a control message that is instruction information that is transmitted from the base station and that requires instruction handling processing by the CPU .
The communication quality determination unit
The average RSSI obtained by averaging the RSSI of the signal received from the base station is compared with a preset average RSSI threshold, and it is determined that the event has occurred when the average RSSI is lower than the average RSSI threshold. An RSSI determination unit,
An averaged FER obtained by averaging FERs based on communication errors generated in communication with the base station is compared with a preset average FER threshold value, and the event is detected when the averaged FER is higher than the average FER threshold value. A method for controlling a mobile communication terminal comprising:
An event monitoring step for monitoring whether an event requiring processing by the CPU has occurred during communication with the base station;
A mode switching step of outputting an interrupt signal to the CPU when the event occurs, and switching the CPU from a sleep mode that is a sleep state to a normal mode that processes the event;
A method for controlling a mobile communication terminal, comprising:

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